This invention relates to a method for uniformly dividing fluid streams into two or more partial fluid streams in chemical apparatuses which, compared with conventional devices, have a reduced tendency to form deposits.
In chemical technology, the chemical reaction apparatuses that are used frequently employ devices for the uniform distribution of fluid streams within the reaction apparatuses. Such devices are frequently also referred to as internals.
A specific form of such internals are so-called plates, among which so-called distributor plates form a special case. Such distributor plates are frequently used in chemical reaction apparatuses, such as, for example, columns or heat exchangers.
Such distributor plates are conventionally in the form of a flat horizontal surface (the plate) provided with apertures through which the particular fluid stream enters the remainder of the chemical apparatus. As a result of the flow through the apertures, zones characterised by a reduced fluid velocity or by a recirculation flow conventionally form on the distributor plate at sites of geometric irregularity (e.g. 90° angle at openings or apertures such as drilled holes, etc.).
When the fluid entering the chemical reaction apparatus through the openings or apertures contains dissolved substances or suspensions of particles, deposits of those substances and/or particles conventionally form in zones with reduced fluid velocity or recirculation flow. This phenomenon is generally known and is described, for example, in H. Mülller-Steinhagen “Heat-Exchanger Fouling-Mitigation and Cleaning Technologies” Publico Publications, pp. 8-9, Essen 2000. ISBN 3-934736-00-9.
IN-A-192183 discloses a device which is said to permit the uniform distribution of liquids in columns. This device is characterised by a main distributor (10) and secondary distributors (11) connected thereto, which are in turn connected to the actual distributing distributor plates (4) via a pipe (2). The actual uniform distribution of the liquid is effected by dripping down from the distributor plate (4) along guide walls (5), which are structured and are arranged around the distributor plate (4), leaving a narrow gap. The precise geometric form of the apertures present in the device is not disclosed. The reference numerals used here relate to the reference numerals used in IN-A-192183.
The device described in IN-A-192183 is disadvantageous in particular because the narrow gap between the distributor plate (4) and the guide wall (5) forms a zone in which the flow of the liquid is slowed down considerably and may be subjected to recirculation. Therefore, when such a device is used, it is assumed that deposits of substances dissolved/suspended in the liquid will occur. The device further comprises many sites of geometric irregularity, such as the edge of the distributor plate (4) as well as the bores of the discharge openings (12), at which the formation of deposits is very probable for the above-mentioned reasons.
DE-A-2 752 391 discloses a device for the uniform distribution of liquids which consists of parallel channels with overflow edges (3, 6) having V-shaped liquid outlet openings. The amount of liquid distributed is determined by adjusting an interval (7) between two parallel overflow edges, as well as by the size and number of V-shaped liquid outlet openings. The precise geometric form of the V-shaped liquid outlet openings, and in particular the angle of incidence, are not disclosed. The reference numerals used here relate to the reference numerals used in DE-A-2 752 391.
The device described in DE-A-2 752 391 has a large number of sites of geometric irregularity. For example, both the edge of the V-shaped liquid outlet openings and the overflow edge are characterised by such geometric irregularities. It is therefore to be assumed that reduced liquid velocities and/or recirculation flows will occur in particular at such sites, and deposits will thus form if the liquid to be distributed contains dissolved/suspended substances.